Display panel, display device, and display panel manufacturing method

ABSTRACT

A display panel includes: a substrate; a light emitting element array that is disposed above the substrate in an image display region; a peripheral electrode that is disposed above the substrate in a peripheral region, the peripheral region being located outside the image display region in plan view; a lyophilic insulating layer that is disposed on the peripheral electrode; and a peripheral bank that includes a liquid-repellent resin material including fluorine, and has an outer edge that overlaps the peripheral electrode in the peripheral region in plan view. The lyophilic insulating layer includes a resin material having a lower percentage of fluorine than the peripheral bank. At least a corner part of a bottom surface of the peripheral bank is disposed on the lyophilic insulating layer.

This application claims priority to Japanese Patent Application No.2018-086954 filed Apr. 27, 2018, the contents of which are herebyincorporated by reference in their entirety.

BACKGROUND OF DISCLOSURE Technical Field

The present disclosure relates to display panels that useelectroluminescence (EL) elements that make use of electroluminescence,and display devices using the same.

Description of Related Art

Recently, organic EL display panels in which organic EL elements arearranged in a matrix on a substrate are being realized as display panelsused in display devices such as digital televisions.

In such organic EL display panels, light emitting layers of organic ELelements of are typically partitioned from adjacent organic EL elementsby an insulating layer including an insulating material. Each organic ELelement has a configuration in which a functional film such as a lightemitting layer containing an organic light emitting material is disposedbetween an electrode pair of an anode and a cathode, and when driven, avoltage is applied between the electrode pair and light is emittedthrough recombination of holes injected to the light emitting layer fromthe anode and electrons injected to the light emitting layer from thecathode.

Recently, as display devices have increased in size, a wet process hasbeen proposed as an efficient method of forming a functional film, inwhich ink containing a functional material is applied based on a methodsuch as an inkjet method. A wet process has merit in that positionalprecision when separately applying functional films does not depend onsubstrate size, and therefore the technical barrier to increasingdisplay device size is relatively low. An organic EL display panelformed by the wet process typically includes a bank disposed on asubstrate and light emitting layers formed in a region partitioned bythe bank.

Examples of bank arrangement are as follows. One is a pixel bankstructure in which banks are arranged in a lattice form to partition aregion for each light emitting unit. The other is a line bank structurein which banks each extending in one direction are arranged to partitiona region for each column of light emitting units arranged in the onedirection (see Japanese Patent Application Publication No. 2009-43499).In such a line bank structure, a liquid-repellent material is used forbanks or a treatment for adding liquid-repellency to surfaces of banksis performed in order to prevent for example color mixture caused by inkspread beyond the banks.

SUMMARY

The present disclosure includes a display panel in which a bank disposedon an electrode in a peripheral region is prevented from separating.

A display panel pertaining to at least one embodiment of the presentdisclosure is a display panel including: a substrate; a light emittingelement array that is disposed above the substrate in an image displayregion; a peripheral electrode that is disposed above the substrate in aperipheral region, the peripheral region being located outside the imagedisplay region in plan view; a lyophilic insulating layer that isdisposed on the peripheral electrode; and a peripheral bank thatincludes a liquid-repellent resin material including fluorine, and hasan outer edge that overlaps the peripheral electrode in the peripheralregion in plan view. The lyophilic insulating layer includes a resinmaterial having a lower percentage of fluorine than the peripheral bank.At least a corner part of a bottom surface of the peripheral bank isdisposed on the lyophilic insulating layer.

According to a display panel pertaining to at least aspect of thepresent disclosure, separation of a peripheral bank is prevented andthis reduces influence of a peripheral bank forming process on displaypanels, thereby achieving display panels with a stable quality.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages, and features of the technologypertaining to the present disclosure will become apparent from thefollowing description thereof taken in conjunction with the accompanyingdrawings, which illustrate at least one embodiment of the technologypertaining to the present disclosure.

FIG. 1 is a schematic plan view of configuration of a display panel 10pertaining to at least one embodiment;

FIG. 2 is a schematic enlarged plan view of a portion X0 in FIG. 1,indicating the configuration of the display panel 10 pertaining to atleast one embodiment;

FIGS. 3A and 3B are schematic cross sections respectively taken along aline A-A and a line B-B in FIG. 2, indicating the configuration of thedisplay panel 10 pertaining to at least one embodiment;

FIG. 4 is a flow chart of a manufacturing method of the display panel 10pertaining to at least one embodiment;

FIGS. 5A to 5E are partial cross sections taken along the line A-A inFIG. 2, indicating part of a manufacturing process of the display panel10 pertaining to at least one embodiment, where FIG. 5A indicates astate where a substrate is formed, FIG. 5B indicates a state where apixel electrode material layer is formed on the substrate, FIG. 5Cindicates a state where pixel electrodes and a peripheral electrode areformed by patterning the pixel electrode material layer, FIG. 5Dindicates a state where a first resist layer is applied onto the pixelelectrodes, the peripheral electrode, and an interlayer insulatinglayer, and FIG. 5E indicates a state where row banks and a lyophilicinsulating layer are formed on the pixel electrodes, the peripheralelectrode, and the interlayer insulating layer;

FIGS. 6A to 6D are partial cross sections taken along the line A-A inFIG. 2, indicating part of the manufacturing process of the displaypanel 10 pertaining to at least one embodiment, where FIG. 6A indicatesa state where a second resist layer is applied, FIG. 6B indicates astate where column banks and a peripheral bank are formed, FIG. 6Cindicates a state where hole injection layers, hole transport layers,light emitting layers, an electron transport layer, and an electroninjection layer are formed in an image display region, and FIG. 6Dindicates a state where a common electrode and a sealing layer areformed;

FIGS. 7A to 7E are partial cross sections taken along the line B-B inFIG. 2, indicating part of the manufacturing process of the displaypanel 10 pertaining to at least one embodiment, where FIG. 7A indicatesa state where the substrate is formed, FIG. 7B indicates a state wherethe pixel electrode material layer is formed on the substrate, FIG. 7Cindicates a state where the pixel electrodes and the peripheralelectrode are formed by patterning the pixel electrode material layer,FIG. 7D indicates a state where the first resist layer is applied ontothe pixel electrodes, the peripheral electrode, and the interlayerinsulating layer, and FIG. 7E indicates a state where the row banks andthe lyophilic insulating layer are formed on the pixel electrodes, theperipheral electrode, and the interlayer insulating layer;

FIGS. 8A to 8D are partial cross sections taken along the line B-B inFIG. 2, indicating part of the manufacturing process of the displaypanel 10 pertaining to at least one embodiment, where FIG. 8A indicatesa state where the second resist layer is applied, FIG. 8B indicates astate where the column banks and the peripheral bank are formed, FIG. 8Cindicates a state where the hole injection layers, the hole transportlayers, the light emitting layers, the electron transport layer, and theelectron injection layer are formed in the image display region, andFIG. 8D indicates a state where the common electrode and the sealinglayer are formed;

FIGS. 9A to 9C are partial plan view corresponding to FIG. 2, indicatingpart of the manufacturing process of the display panel 10 pertaining toat least one embodiment, where FIG. 9A indicates a state where the pixelelectrodes and the peripheral electrode are formed, FIG. 9B indicates astate where the row banks and the lyophilic insulating layer are formed,and FIG. 9C indicates a state where the column banks and the peripheralbank are formed;

FIG. 10 is a schematic plan view of configuration of a display panel ina comparative example pertaining to at least one embodiment, beingsimilar to FIG. 2;

FIGS. 11A and 11B are schematic cross sections respectively taken alonglines C-C and D-D in FIG. 10, indicating the configuration of thedisplay panel in the comparative example pertaining to at least oneembodiment; and

FIG. 12 is a schematic block diagram of configuration of a displaydevice pertaining to at least one embodiment.

DETAILED DESCRIPTION

According to an application method of forming light emitting layers,functional layers, and the like, an ink in which material has beendissolved is applied to gaps between banks. As described above,liquid-repellency is added to top portions and side portions of thebanks in order to prevent ink spread beyond the banks. Ink is applied toa region that is to be an image display region where light emittingelements are formed. Accordingly, it is unfavorable that the ink leaksinto a region that is to be a peripheral region located outside theimage display region from a viewpoint of control on film thickness oflight emitting layers and functional layers and a viewpoint of formationof the peripheral region. Thus, a peripheral bank should preferably beformed in order to partition between the image display region and theperipheral region, which is located outside the image display region.Also, the peripheral bank should preferably have liquid-repellency inorder to prevent ink spread beyond the peripheral bank.

By the way, a peripheral electrode surrounding the image display regionshould preferably be formed in the peripheral region. In light emittingelements of a so-called top emission type, a common electrode serving asa counter electrode is required to be light transmissive, andaccordingly usually includes conductive oxide such as indium tin oxide(ITO) and indium zinc oxide (IZO). However, such a conductive oxide hasa high sheet resistance of compared to metal. Accordingly, in especiallylarge-sized display panels, a metal material should preferably be usedfor forming a peripheral electrode that is to be disposed in aperipheral region and auxiliary electrodes that are to be provided ingaps between light emitting elements in an image display region.Particularly, the peripheral electrode usually doubles as an electrodefor feeding electrical power to the auxiliary electrodes, andaccordingly should preferably have a large surface. On the other hand,in the case where the peripheral electrode and the peripheral bank areseparated from each other, an area of the peripheral region increasesand this decreases a proportion of the image display region in thedisplay panel. Also, pixel electrodes are required to belight-reflective and accordingly usually include a metal material. Thus,the use of the same material is possible for forming pixel electrodesand a peripheral electrode. In view of this, it is effective that asingle metal layer is patterned to collectively form pixel electrodesand a peripheral electrode in terms of simplification of manufacturingprocesses, compared to the case where a process of forming a peripheralelectrode and a process of forming pixel electrodes are individuallyperformed. Here, a distance between outermost ones of the pixelelectrodes and the peripheral electrode is set to approximately adistance between the pixel electrodes, and the inner edge of theperipheral electrode is covered with the peripheral bank, which is aninsulating layer. This facilitates to set a minimum space between theimage display region and the peripheral region.

However, the inventors found the following problem in the aboveconfiguration. A peripheral electrode should preferably include a metalmaterial having a low sheet resistance and a high reflectivity forvisible light, such as aluminum and alloy of aluminum. In contrast, atleast a surface of a peripheral bank should preferably beliquid-repellent, and accordingly includes fluorine compound. Due tothis, in the case where the peripheral bank is disposed directly on theperipheral electrode, the fluorine compound which is included in theperipheral bank sometimes affects the peripheral electrode.Particularly, in the case where the peripheral bank includes aphotosensitive resin material containing fluorine compound (so-calledphotoresist), the peripheral electrode is exposed to a developercontaining fluorine compound during a peripheral bank developingprocess. This results in elution of a surface part of the peripheralelectrode exposed to the developer due to the fluorine compound. In thecase where the surface part of the peripheral electrode elutes at acontact interface between the peripheral bank and the peripheralelectrode, the adhesion between the peripheral bank and the peripheralelectrode decreases, and thus the peripheral bank might separate from asubstrate.

Furthermore, separation between a bank and a peripheral electrode suchas the above case might occur in other cases, such as a case where aframe-shaped bank is disposed on part of a peripheral electrode in orderto constitute dummy pixels. In such a case, a direct contact between theframe-shaped bank and the peripheral electrode might result inseparation of the frame-shaped bank likewise. Moreover, in the casewhere an isolated bank that is linear or curved is disposed on aperipheral electrode, a direct contact between the isolated bank and theperipheral electrode might result in separation of the isolated banklikewise.

Furthermore, in the case where a peripheral bank or the like includesnot so-called photoresist but non-photosensitive resin, a contactinterface between the peripheral bank and a peripheral electrode isexposed to an etching gas, an etching solution, or the like during apatterning process. Thus, a similar problem inevitable occurs when aperipheral bank including fluorine is in direct contact with anelectrode.

In view of the above, the inventors have made studies on a configurationfor improving the adhesion between a peripheral electrode and aliquid-repellent bank disposed on the peripheral electrode in a displaypanel, and as a result have conceived of at least one aspect of thepresent disclosure.

A display panel pertaining to at least one embodiment of the presentdisclosure is a display panel including: a substrate; a light emittingelement array that is disposed above the substrate in an image displayregion; a peripheral electrode that is disposed above the substrate in aperipheral region, the peripheral region being located outside the imagedisplay region in plan view; a lyophilic insulating layer that isdisposed on the peripheral electrode; and a peripheral bank thatincludes a liquid-repellent resin material including fluorine, and hasan outer edge that overlaps the peripheral electrode in the peripheralregion in plan view. The lyophilic insulating layer includes a resinmaterial having a lower percentage of fluorine than the peripheral bank.At least a corner part of a bottom surface of the peripheral bank isdisposed on the lyophilic insulating layer.

According to a display panel pertaining to at least aspect of thepresent disclosure, separation of a peripheral bank is prevented andthis reduces influence of a peripheral bank forming process on displaypanels, thereby achieving display panels with a stable quality.

A display panel pertaining to at least one embodiment of the presentdisclosure is a display panel including: a substrate; a light emittingelement array that is disposed above the substrate in an image displayregion; a peripheral electrode that is disposed above the substrate in aperipheral region, the peripheral region being located outside the imagedisplay region in plan view; a lyophilic insulating layer that isdisposed on the peripheral electrode; and a peripheral bank thatincludes a liquid-repellent resin material including fluorine. Thelyophilic insulating layer includes a resin material having a lowerpercentage of fluorine than the peripheral bank. A part of an outer edgeof the peripheral bank overlaps the peripheral electrode in theperipheral region in plan view. At least the part of the outer edge ofthe peripheral bank is disposed on the lyophilic insulating layer.

According to a display panel pertaining to at least aspect of thepresent disclosure, separation of a peripheral bank is prevented andthis reduces influence of a peripheral bank forming process on a displaypanel, thereby achieving display panels with a stable quality.

According to at least one embodiment of the display panel, the resinmaterial of the lyophilic insulating layer includes no fluorine.

With the above configuration, the lyophilic insulating layer exerts noinfluence on the peripheral region, thereby achieving display panelswith a more stable quality.

According to at least one embodiment of the display panel, theperipheral bank partitions between the image display region and theperipheral region.

With the above configuration, the peripheral bank, which isliquid-repellent, prevents material of the light emitting element arrayfrom leaking into the peripheral region.

According to at least one embodiment of the display panel, an outer edgeof the lyophilic insulating layer is located outside the outer edge ofthe peripheral bank in plan view.

With the above configuration, the peripheral bank is further stronglyprevented from exerting an influence on the peripheral electrode,thereby achieving display panels with a stable quality.

According to at least one embodiment of the display panel, an outer edgeof the lyophilic insulating layer coincides with the outer edge of theperipheral bank in plan view.

With the above configuration, area minimization of the lyophilicinsulating layer is possible.

According to at least one embodiment of the display panel, the lightemitting element array includes light emitting elements that includepixel electrodes, a functional layer, and a common electrode. Theperipheral electrode and the pixel electrodes include a same material.

With the above configuration, simultaneous formation of the peripheralelectrode and the pixel electrodes is possible, thereby manufacturingdisplay panels in a more convenient and efficient manner.

According to at least one embodiment of the display panel, theperipheral electrode is electrically connected with the commonelectrode.

With the above configuration, efficient electrical power feeding whilesuppressing voltage decrease is possible.

According to at least one embodiment of the display panel, the lightemitting element array includes: light emitting elements that aredisposed in a matrix of rows and columns; column banks that include aliquid-repellent resin material, extend in a column direction, andpartition between the light emitting elements in a row direction; androw banks that include a resin material having a lower liquid repellencythan the column banks, and partition between the light emitting elementsin the column direction. The lyophilic insulating layer and the rowbanks include a same material.

With the above configuration, simultaneous formation of the lyophilicinsulating layer and the row banks is possible, thereby manufacturingdisplay panels in a more convenient and efficient manner.

According to at least one embodiment of the display panel, theperipheral bank and the column banks include a same material.

With the above configuration, simultaneous formation of the peripheralbank and the column banks is possible, thereby manufacturing displaypanels in a more convenient and efficient manner.

A display device pertaining to at least one embodiment of the presentdisclosure is a display device including a display panel pertaining toat least one embodiment of the present disclosure.

Also, a method of manufacturing a display panel pertaining to at leastone embodiment of the present disclosure is a method of manufacturing adisplay panel having an image display region and a peripheral region.The peripheral region is located outside the image display region inplan view. The method includes forming pixel electrodes above asubstrate in a range corresponding to the image display region. Themethod further includes forming a peripheral electrode above thesubstrate in a range corresponding to the peripheral region. The methodfurther includes forming a lyophilic insulating layer and row banks byusing a photosensitive resin material. The lyophilic insulating layercovers at least an inner edge of the peripheral electrode, and the rowbanks partition between the pixel electrodes in a column direction. Themethod further includes forming a peripheral bank and column banks byusing a photosensitive resin material having a higher percentage offluorine than the photosensitive resin material of the lyophilicinsulating layer. At least a corner part of a bottom surface of theperipheral bank is disposed on the lyophilic insulating layer, and thecolumn banks partition between the pixel electrodes in a row direction.The method further includes forming a functional layer above the pixelelectrodes. The method further includes forming a common electrode abovethe functional layer and the peripheral electrode.

Moreover, a method of manufacturing a display panel pertaining to atleast one embodiment of the present disclosure is a method ofmanufacturing a display panel having an image display region and aperipheral region. The peripheral region is located outside the imagedisplay region in plan view. The method includes forming pixelelectrodes above a substrate in a range corresponding to the imagedisplay region. The method further includes forming a peripheralelectrode above the substrate in a range corresponding to the peripheralregion. The method further includes forming a lyophilic insulating layerand row banks by using a photosensitive resin material. The lyophilicinsulating layer covers at least an inner edge of the peripheralelectrode, and the row banks partition between the pixel electrodes in acolumn direction. The method further includes forming a peripheral bankand column banks by using a photosensitive resin material having ahigher percentage of fluorine than the photosensitive resin material ofthe lyophilic insulating layer. An outer edge of the peripheral bank islocated inside an outer edge of the lyophilic insulating layer, and thecolumn banks partition between the pixel electrodes in a row direction.The method further includes forming a functional layer above the pixelelectrodes. The method further includes forming a common electrode abovethe functional layer and the peripheral electrode.

A display panel manufactured by a display panel manufacturing methodpertaining to at least one embodiment of the present disclosure includesa peripheral bank that exercises no influence on a peripheral electrode,and thus has an improved adhesion between the peripheral bank and theperipheral electrode. This helps to manufacture display panels in a moreconvenient and efficient manner by the display panel manufacturingmethod.

1. Overall Configuration of Display Panel 10

1.1 Outline

An organic light emitting display panel 10 (hereinafter, display panel10) as an embodiment of a display panel pertaining to at least oneembodiment is described with reference to the drawings. The drawings areschematic diagrams and actual scale may differ.

FIG. 1 is a schematic plan view of the display panel 10 pertaining to atleast one embodiment.

The display panel 10 is an organic EL display panel that useselectroluminescence of an organic compound, and has light emittingelements (organic EL elements 100), which form pixels, disposed in amatrix of rows and columns on a substrate 100 x (thin film transistor(TFT) substrate) on which TFTs are disposed. The display panel 10 has atop-emission configuration, emitting light from an upper surface. Here,in the present disclosure, the X direction, the Y direction, and the Zdirection in FIG. 1 correspond to the row direction, the columndirection, and the thickness direction of the display panel 10,respectively.

In FIG. 1, the display panel 10 is composed of an image display region10 a in which the organic EL elements 100 are arranged in the matrix ofrows and columns and a peripheral region 10 b surroundings the imagedisplay region 10 a. The image display region 10 a is partitioned in thematrix by column banks 522Y partitioning the organic EL elements 100 inthe row direction and row banks 122X partitioning the organic ELelements 100 in the column direction. A peripheral bank 320 is formed ata boundary between the image display region 10 a and the peripheralregion 10 b so as to surround the image display region 10 a. Aperipheral electrode 300 is formed in the peripheral region 10 b so asto surround the peripheral bank 320. Further, though not in FIG. 1, asealing member is formed so as to surround the peripheral electrode 300.

1.2 Configuration of Components Near Peripheral Bank 320

FIG. 2 is an enlarged plan view of a portion X0 in FIG. 1 pertaining toat least one embodiment.

In the image display region 10 a of the display panel 10, unit pixels100 e corresponding to the organic EL display elements 100 are arrangedin a matrix.

In each of the unit pixels 100 e, three self light emitting regions 100a are formed, which are regions that emit light via an organic compound,namely, a self red light emitting region 100 aR, a self green lightemitting region 100 aG, and a self blue light emitting region 100 aB(hereinafter, where a distinction between 100 aR, 100 aG, and 100 aB isnot necessary, 100 a is used). That is, three sub pixels 100 secorresponding to self light emitting regions 100 aR, 100 aG, and 100 aBlined up in the row direction in FIG. 2 are one set, and make up one ofthe unit pixels 100 e in a color display.

Further, in FIG. 2, the display panel 10 includes pixel electrodes 119that are arranged in a matrix on the substrate 100 x at predefinedintervals in the row and column directions. Each of the pixel electrodes119 has a rectangular shape in plan view. The pixel electrodes 119arranged in a matrix correspond to the three self light emitting regions100 aR, 100 aG, 100 aB lined up in the row direction.

In the display panel 10, shapes of the banks 122 are that of a so-calledline-like insulating layer form. The column banks 522Y extend in thecolumn direction (Y direction in FIG. 2) and are lined up in the rowdirection above regions on the substrate 100 x between outer edges inthe row direction of two adjacent ones of the pixel electrodes 119 inthe row direction.

On the other hand, the row banks 122X extend in the row direction (Xdirection in FIG. 2) and are lined up in the column direction aboveregions on the substrate 100 x between outer edges in the columndirection of two adjacent ones of the pixel electrodes 119 in the columndirection. A region in which the row banks 122X are formed becomes anon-self light emitting region 100 b, because organicelectroluminescence does not occur in light emitting layers 123 abovethe pixel electrodes 119. Thus, edges in the column direction of theself light emitting regions 100 a are defined by edges in the columndirection of the row banks 122X.

Where a gap 522 z between adjacent ones of the column banks 522Y isdefined, a red gap 522 zR corresponding to the self light emittingregion 100 aR, a green gap 522 zG corresponding to the self lightemitting region 100 aG, or a blue gap 522 zB corresponding to the selflight emitting region 100 aB exists (hereinafter, where distinctionbetween gap 522 zR, gap 522 zG, and gap 522 zB is not required, “gap 522z” is used). In the display panel 10, the column banks 522Y and the gaps522 z alternate in the row direction.

Further, in FIG. 2, in the display panel 10, the self light emittingregions 100 a and the non-self light emitting regions 100 b alternate inthe column direction along the gap 522 z. In the non-self light emittingregion 100 b, there is a connecting recess 119 c (contact hole) thatconnects one of the pixel electrodes 119 to a source electrode of a TFT,and a contact region 119 b (contact window) on the pixel electrode 119for electrical connection to the pixel electrode 119.

Further, for one sub pixel 100 se, the column banks 522Y and the rowbanks 122X intersect, and the self light emitting region 100 a isdisposed between the row banks 122X in the column direction.

The peripheral electrode 300 is disposed in the peripheral region 10 b,which surrounds the image display region 10 a, so as to surround theimage display region 10 a. Also, the peripheral bank 320 is formed atthe boundary between the peripheral region 10 b and the image displayregion 10 a so as to surround the image display region 10 a. The inneredge of the peripheral bank 320 defines the outer edges of the selflight emitting regions 100 a that are located outermost in the imagedisplay region 10 a. Further, the outer edge of the peripheral bank 320defines the inner edge of the peripheral region 10 b. Moreover, part ofthe peripheral bank 320 including the outer edge is located on theperipheral electrode 300, and a lyophilic insulating layer 310 isinterposed between at least the outer edge of the peripheral bank 320and the peripheral electrode 300. In other words, the outer edge of theperipheral bank 320 is out of direct contact with the peripheralelectrode 300, and is in close contact with the peripheral electrode 300via the lyophilic insulating layer 310.

2. Configuration of Components of Display Panel 10

The following explains the configuration of the organic EL elements 100and the components near the peripheral bank 320 in the display panel 10,with reference to cross-sectional views in FIGS. 3A and 3B. FIG. 3A is aschematic cross section taken along a line A-A in FIG. 2 pertaining toat least one embodiment. FIG. 3B is a schematic cross section takenalong a line B-B in FIG. 2 pertaining to at least one embodiment.

The display panel 10 pertaining to at least one embodiment includes thesubstrate 100 x (TFT substrate) on which the TFTs are formed in a lowerpart in the Z-axis direction and organic EL element units are formedthereon.

(1) Substrate 100 x

The substrate 100 x includes a base material that is an insulatingmaterial, a TFT layer, and an interlayer insulating layer. The TFT layerhas drive circuits formed therein for the respective sub pixels 100 se.

The base material is for example a glass substrate, a quartz substrate,a silicon substrate, a metal substrate including molybdenum sulfide,copper, zinc, aluminum, stainless, magnesium, iron, nickel, gold,silver, or the like, a semiconductor substrate including galliumarsenide or the like, or a plastic substrate. Both thermoplastic resinand thermosetting resin are usable as a plastic material of the basematerial. The plastic material is for example a single layer of any onetype of the following materials or a laminate of any two or more typesof the following materials selected so as to be resistant against theprocess temperature. The materials include polyimide (PI), polyeterimide (PEI), polysulfone (PSU), polycarbonate (PC), polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polybutyleneterephthalate, thermoplastic elastomer such as styrene elastomer,polyolefin elastomer, and polyurethane elastomer, epoxy resin,unsaturated polyester resin, silicone resin, polyurethane, or copolymer,blend, polymer alloy or the like including such a material as a maincomponent.

The interlayer insulating layer includes a resin material, and isprovided for flattening unevenness on an upper surface of the TFT layer.The resin material is for example a positive photosensitive material.Examples of the photosensitive material include acrylic resin, polyimideresin, siloxane resin, and phenol resin.

(1) Pixel Electrodes 119 and Peripheral Electrode 300

On the interlayer insulating layer, which is positioned on the uppersurface of the substrate 100 x, while the pixel electrodes 119 areprovided in units of the sub pixels 100 se in the image display region10 a, the peripheral electrode 300, which surrounds the image displayregion 10 a, is provided in the peripheral region 10 b.

The pixel electrodes 119 are provided for supplying carriers to thelight emitting layers 123. For example, when functioning as anodes, thepixel electrodes 119 supply holes to the light emitting layers 123. Thepixel electrodes 119 are rectangular and plate-like. The pixelelectrodes 119 are arranged on the substrate 100 x with predefinedintervals therebetween in the row direction and with predefinedintervals therebetween in the column direction in the gaps 522 z. Also,the connection recesses 119 c of the pixel electrodes 119, which arerecessed towards the substrate 100 x, are connected with the sourceelectrodes of the TFTs through contact holes which are provided in theupper surface of the substrate 100 x.

The peripheral electrode 300 is provided for supplying carriers to acommon electrode 126 which is described later. For example, when thepixel electrodes 119 function as anodes, the peripheral electrode 300supplies electron to the common electrode 126 serving as a counterelectrode. The peripheral electrode 300 is frame-shaped and plate-like.The peripheral electrode 300 is disposed on the substrate 100 x at apredefined interval in the row direction and a predefined interval inthe column direction from ones of the pixel electrodes 119 that arelocated outermost in the image display region 10 a.

The pixel electrodes 119 and the peripheral electrode 300 each include ametal layer including a light-reflective metal material. Specificexamples of the light-reflective metal material include silver (Ag),aluminum (Al), alloy of aluminum, molybdenum (Mo), alloy of silver,palladium, and copper (APC), alloy of silver, rubidium, and gold (ARA),alloy of molybdenum and chromium (MoCr), alloy of molybdenum andtungsten (MoW), and alloy of nickel and chromium (NiCr).

In at least one embodiment, the pixel electrodes 119 and the peripheralelectrode 300 each have a single-layer structure of a metal layer. Also,in at least one embodiment, the pixel electrodes 119 and the peripheralelectrode 300 each have a multi-layer structure including a metal oxidelayer, such as an indium tin oxide (ITO) layer and an indium zinc oxide(IZO) layer, layered on a metal layer.

(3) Hole Injection Layers 120 and Hole Transport Layers 121

The hole injection layers 120 are provided on the pixel electrodes 119in order to promote injection of holes from the pixel electrodes 119 tothe light emitting layers 123. Specific examples of material of the holeinjection layers 120 include a conductive polymer material such asPEDOT/PSS (mixture of polythiophene and polystyrene sulfonate).

In at least one embodiment, the hole injection layers 120 include oxideof transition metal. Specific examples of transition metal includesilver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W),nickel (Ni), and iridium (Ir). The reason why oxide of transition metalis used is that oxide of transition metal has a plurality of oxidationnumbers, and this facilitates hole injection, contributing to reductionin driving voltage. In at least one embodiment, the hole injectionlayers 120 have a high work function.

The hole transport layers 121 have a function of transporting holesinjected from the hole injection layers 120 to the light emitting layers123. The hole transport layers 121 include an organic material having ahigh hole mobility in order to efficiently transport holes from the holeinjection layers 120 to the light emitting layers 123. The holetransport layers 121 are formed by applying and drying a solution of anorganic material. The organic material of the hole transport layers 121is for example a high-molecular compound such as polyfluorene,polyfluorene derivative, polyallylamine, and polyallylamine derivative.

Also, in at least one embodiment, the hole transport layers 121 includestriazole derivative, oxadiazole derivative, imidazole derivative,polyarylalkane derivative, pyrazoline derivative and pyrazolonederivative, phenylenediamine derivative, arylamine derivative,amino-substituted chalcone derivative, oxazole derivative,styrylanthracene derivative, fluorenone derivative, hydrazonederivative, stilbene derivative, porphyrin compound, aromatic tertiaryamine compound and styrylamine compound, butadiene compound, polystyrenederivative, hydrazone derivative, triphenylmethane derivative, ortetraphenylbenzene derivative. In at least one embodiment, the holetransport layers 121 include porphyrin compound, aromatic tertiary aminecompound, styrylamine compound, or the like. In this case, the holetransport layers 121 are formed by a vacuum deposition method. Thematerial and the manufacturing method of the hole transport layers 121are not limited to those described above. In at least one embodiment,the hole transport layers 121 is formed by using any material having ahole transport function and any manufacturing method usable formanufacturing the hole transport layers 121.

(4) Banks 122

The banks 122 include an insulator and are formed to cover edges of thepixel electrodes 119, the hole injection layers 120, and the holetransport layers 121. The banks 122 include the column banks 522Yextending in the column direction and arranged along the row directionand the row banks 122X extending in the row direction and arranged alongthe column direction. In FIG. 2, the column banks 522Y intersect the rowbanks 122X, forming a lattice shape. Further, upper surfaces of thecolumn banks 522Y are positioned higher than upper surfaces of the rowbanks 122X.

The row banks 122X each have a line-like shape extending in the rowdirection, and in cross section taken along the column direction have atapered trapezoidal shape tapering upwards. The row banks 122X extend inthe row direction, perpendicular to the column direction, passingthrough the column banks 522Y. The upper surfaces of the row banks 122Xare positioned lower than the upper surfaces of the column banks 522Y.Thus, the row banks 122X and the column banks 522Y form openingscorresponding to the self light emitting regions 100 a.

The row banks 122X are for controlling flow in the column direction ofink containing an organic compound that is a material of the lightemitting layers 123. Thus, the row banks 122X have a lyophilic propertywith respect to the ink that is not less than a predefined value.According to this configuration, fluidity of the ink in the columndirection is increased to suppress variation of applied ink amountbetween sub pixels. The pixel electrodes 119 are not exposed in regionsother than the self light emitting regions 100 a, which are partitionedby the row banks 122X and the column banks 522Y. Regions in which therow banks 122X are present do not emit light and thus do not contributeto luminance.

When an upper limit of film thickness of the row banks 122X is thickerthan 2000 nm, wet spreading of the ink is poor, and when 1200 nm orless, wet spreading of the ink is further improved. Further, when alower limit of film thickness is at least 100 nm, end portions of thepixel electrodes 119 are covered with the banks 122, and the pixelelectrodes 119 and the counter electrode 125 can be manufactured at aconstant yield without short-circuits. When the lower limit of filmthickness is at least 200 nm, short defects are reduced making stablemanufacturing possible. In a case in which connecting groove portionsare provided in the banks 122, the same applied to film thickness at abottom of the groove portions.

Accordingly, in at least one embodiment, thickness of the row banks 122Xranges from 100 nm to 2000 nm. In at least one embodiment, thickness ofthe row banks 122X ranges from 200 nm to 1200 nm. According to at leastone embodiment, thickness of the row banks 122X is approximately 1000nm.

The column banks 522Y block flow of the ink, which contains the organiccompound that is the material of the light emitting layers 123, in therow direction to define row direction outer edges of the light emittinglayers 123. The column banks 522Y each have a line-like shape extendingin the column direction, and in cross section taken along the rowdirection have a tapered trapezoidal shape tapering upwards.

The column banks 522Y define outer edges in the row direction of theself light emitting region 100 a of each of the sub pixels 100 se. Thus,the column banks 522Y have liquid repellency with respect to the inkthat is not less than a predefined value.

In at least one embodiment, the thickness of the column banks 522Yranges from 100 nm to 5000 nm. In at least one embodiment, the thicknessof the column banks 522Y range from 200 nm to 3000 nm. According to atleast one embodiment, the thickness of the column banks 522Y isapproximately 2000 nm.

In order to help prevent current leakage in the thickness direction (Zdirection) between outer edges of the pixel electrodes 119 and thecommon electrode 126, the row banks 122Y and the column banks 522Y havean insulation property with a volume resistivity of 1×10⁶Ω cm or more.Thus, as described later, the row banks 122Y and the column banks 522Yare configured to include a predefined insulating material.

The column banks 522Y include a base material including an insulatingresin material to which a liquid-repellent surfactant such as fluorinecompound has been added. Examples of the base material, which includesan insulating resin material, include a positive photosensitive materialsuch as acrylic resin, polyimide resin, siloxane resin, and phenolresin. The base material is not limited to a positive photosensitivematerial. In at least one embodiment, a negative photosensitive materialis for example used for the base material. Also, in at least oneembodiment, a non-photosensitive material is for example used for thebase material.

The row banks 122X include a resin material such as a positivephotosensitive material such as acrylic resin, polyimide resin, siloxaneresin, and phenol resin. The resin material is not limited to a positivephotosensitive material. In at least one embodiment, a negativephotosensitive material is for example used for the resin material.Also, in at least one embodiment, a non-photosensitive material is forexample used for the resin material.

(5) Lyophilic Insulating Layer 310 and Peripheral Bank 320

The peripheral bank 320 is formed so as to surround the image displayregion 10 a to define the boundary between the image display region 10 aand the peripheral region 10 b. The peripheral bank 320 is frame-shapedalong the outer edge of the image display region 10 a, and in crosssection taken along a direction perpendicular to an extension direction,has a tapered trapezoidal shape tapering upwards.

The peripheral bank 320 is provided in order to prevent flow of an inkcontaining an organic compound that is a material of the light emittinglayers 123 into the peripheral region 10 b. Thus, the peripheral bank320 has liquid repellency with respect to the ink that is not less thanthe predefined value, as well as the column banks 522Y have. Also, in atleast one embodiment, the peripheral bank 320 has a thickness that isequivalent to or greater than the thickness of the column banks 522Y.

The peripheral bank 320 includes a base material including an insulatingresin material to which a liquid-repellent surfactant such as fluorinecompound has been added. Examples of the base material, which includesan insulating resin material, include a positive photosensitive materialsuch as acrylic resin, polyimide resin, siloxane resin, and phenolresin. The base material is not limited to a positive photosensitivematerial. In at least one embodiment, a negative photosensitive materialis for example used for the base material. Also, in at least oneembodiment, a non-photosensitive material is for example used for thebase material. In at least one embodiment, the peripheral bank 320includes the same material as the column banks 522Y. Furthermore, in atleast one embodiment, integral molding of the peripheral bank 320 andthe column banks 522Y is possible.

The lyophilic insulating layer 310 is provided in order to preventdirect contact of at least the outer edge of the peripheral bank 320with the peripheral electrode 300. The lyophilic insulating layer 310 isframe-shaped, and is located below at least the outer edge of theperipheral bank 320. In cross section taken along a directionperpendicular to an extension direction, the lyophilic insulating layer310 has a tapered trapezoidal shape tapering upwards.

The lyophilic insulating layer 310 functions as a protective layerprotecting the peripheral electrode 300 against liquid-repellentcomponents contained in the material of the peripheral bank 320,specifically against fluorine compound. Thus, the lyophilic insulatinglayer 310 has a low liquid repellency, and has a lower percentage offluorine compound than the peripheral bank 320. In at least oneembodiment, the lyophilic insulating layer 310 includes no fluorinecompound.

The lyophilic insulating layer 310 includes a resin material such as apositive photosensitive material. Specific examples of thephotosensitive material include acrylic resin, polyimide resin, siloxaneresin, and phenol resin. The resin material is not limited to a positivephotosensitive material. In at least one embodiment, a negativephotosensitive material is for example used for the resin material.Also, in at least one embodiment, a non-photosensitive material is forexample used for the resin material. In at least one embodiment, thelyophilic insulating layer 310 includes the same material as the rowbanks 122X. Furthermore, in at least one embodiment, integral molding ofthe lyophilic insulating layer 310 and the row banks 122X is possible.

Note that the percentage of fluorine in the present disclosure indicatesthe percentage of fluorine on the surfaces of the upper surfaces of theperipheral bank 320, the lyophilic insulating layer 310, the columnbanks 522Y, and the row banks 122X. Analysis as to whether F ions are onthe surfaces is performed for example with use of a TOF-SIMS apparatus.According to this method, Bi is used as primary ions, and secondary ionsobtained at approximately 2 nm from the surface are detected in theanalysis for measurement of the percentage of fluorine.

(6) Light Emitting Layers 123

The light emitting layers 123 are formed on the hole transport layers121 inside openings. The light emitting layers 123 each has a functionof emitting light of one of the R, G, and B colors owing torecombination of holes and electrons. Publicly-known materials areusable for a material of the light emitting layers 123.

Examples of an organic light emitting material of the light emittinglayers 123 include phosphor such as oxinoid compound, perylene compound,coumarin compound, azacoumarin compound, oxazole compound, oxadiazolecompound, perinone compound, pyrrolopyrrole compound, naphthalenecompound, anthracene compound, fluorene compound, fluoranthene compound,tetracene compound, pyrene compound, coronene compound, quinolonecompound and azaquinolone compound, pyrazoline derivative and pyrazolonederivative, rhodamine compound, chrysene compound, phenanthrenecompound, cyclopentadiene compound, stilbene compound, diphenylquinonecompound, styryl compound, butadiene compound, dicyanomethylenepyrancompound, dicyanomethylenethiopyran compound, fluorescein compound,pyrylium compound, thiapyrylium compound, selenapyrylium compound,telluropyrylium compound, aromatic aldadiene compound, oligophenylenecompound, thioxanthene compound, cyanine compound, acridine compound,and metal complex of 8-hydroxyquinoline compound, metal complex of2-bipyridine compound, complex of a Schiff base and group III metal,oxine metal complex, and rare earth complex. Also, in at least oneembodiment, the organic light emitting material of the light emittinglayers 123 is a known phosphorescent substance such as metal complexsuch as tris (2-phenylpyridine) iridium. Further, in at least oneembodiment, the light emitting layers 123 for example includes ahigh-molecular compound such as polyfluorene, polyfluorene derivative,polyallylamine, and polyallylamine derivative, or include a mixture of alow-molecular compound and the high-molecular compound.

(7) Electron Transport Layer 124

The electron transport layer 124 is formed on the light emitting layers123, the row banks 122X, and the column banks 522Y inside the imagedisplay region 10 a in common for the sub pixels 100 se. The electrontransport layer 124 has a function of transporting electrons injectedfrom the common electrode 126 to the light emitting layers 123. Theelectron transport layer 124 for example include oxadiazole derivative(OXD), triazole derivative (TAZ), or phenanthroline derivative (BCPBphen).

(8) Electron Injection Layer 125

The electron injection layer 125 is formed on the electron transportlayer 124 inside the image display region 10 a in common for the subpixels 100 se, and has a function of promoting electron injection fromthe common electrode 126 to the light emitting layers 123.

The electron injection layer 125 for example includes an organicmaterial having an electron injection property that is doped with ametal material improving an electron injection property. Here, dopingindicates dispersion of metal atoms or metal ions of a metal materialinto an organic material in a substantially uniform manner, andspecifically indicates formation of a single phase including an organicmaterial and a minute amount of a metal material. In at least oneembodiment, other phase is not present such as a phase only including ametal material and a phase mainly including a metal material, which area metal piece, a metal film, or the like. In at least one embodiment, asingle phase, which includes an organic material and a minute amount ofa metal material, has metal atoms and metal ions at uniformconcentrations. In at least one embodiment, the single phase has metalatoms and metal ions that do not cohere together. In at least oneembodiment, the metal material is selected from alkali metal oralkaline-earth metal. In at least one embodiment, the metal material isselected from Ba or Li. In at least one embodiment, Ba is selected forthe metal material. Also, in at least one embodiment, a doping amount ofthe metal material in the electron injection layer 125 is 5 wt % to 40wt %. In at least one embodiment, the doping amount of the metalmaterial is 20 wt %. The organic material having an electron transportproperty is for example a π-electron low molecular organic material suchoxadiazole derivative (OXD), triazole derivative (TAZ), andphenanthroline derivative (BCP, Bphen).

In at least one embodiment, the electron injection layer 125 includes,on the side of the light emitting layer 123, a fluoride layer includingmetal selected from alkali metal or alkaline-earth metal.

(9) Common Electrode 126

The common electrode 126 is formed on the peripheral electrode 300, thelyophilic insulating layer 310, the peripheral bank 320, and theelectron transport layer 124 in common for these components. The commonelectrode 126 functions as a cathode.

The common electrode 126 is light transmissive and electricallyconductive, and includes at least one of a metal layer including a metalmaterial and a metal oxide layer including metal oxide. The metal layerhas a film thickness of approximately 1 nm to 50 nm for the purpose ofexhibiting light transmissivity. Examples of a material of the metallayer include Ag, Ag alloy mainly containing Ag, Al, and Al alloy mainlycontaining Al. Examples of Ag alloy include magnesium-silver alloy(MgAg) and indium-silver alloy. Ag basically has a low resistivity. Agalloy has excellent heat resistance and corrosion resistance.Accordingly, Ag and Ag alloy are preferable because of keeping anexcellent electric conductivity in a long time. Examples of Al alloyinclude magnesium-aluminum alloy (MgAl) and lithium-aluminum alloy(LiAl). Other alloys are also usable such as lithium-magnesium alloy andlithium-indium alloy. Examples of a material of the metal oxide layerinclude indium tin oxide (ITO) and indium zinc oxide (IZO).

In at least one embodiment, the common electrode 126 has a single-layerstructure of the metal layer or the metal oxide layer. Also, in at leastone embodiment, the common electrode 126 has a multi-layer structure ofthe metal oxide layer layered on the metal layer or the metal layerlayered on the metal oxide layer.

(10) Sealing Layer 127

A sealing layer 127 is provided on the common electrode 126. The sealinglayer 127 has a function of preventing intrusion of impurities such asmoisture and oxide from the side opposite to the substrate 100 x to thecommon electrode 126, the electron injection layer 125, the electrontransport layer 124, the light emitting layers 123, and the like,thereby suppressing degradation of these layers due to the impurities.The sealing layer 127 includes a light transmissive material such assilicon nitride (SiN) and silicon oxynitride (SiON). In at least oneembodiment, a resin sealing layer that includes a resin material such asacrylic resin and silicone resin is provided on a layer that includes amaterial such as silicon nitride (SiN) and silicon oxynitride (SiON).

In at least one embodiment, since the display panel 10 is of thetop-emission type, the sealing layer 127 includes a light transmissivematerial.

Although not in FIGS. 3A and 3B, in at least one embodiment, a colorfilter and/or an upper substrate is adhered onto the sealing layer 127via a sealing resin. Adhesion of an upper substrate helps to prevent thehole injection layers 120, the hole transport layers 121, the lightemitting layers 123, the electron transport layer 124, the electroninjection layer 125, and the common electrode 126 against moisture, air,and so on.

3. Effect by Display Panel 10 Pertaining to at Least One Embodiment

The following describes differences between the display panel 10 havingthe lyophilic insulating layer 310 pertaining to at least one embodimentand an organic light emitting panel having no lyophilic insulatinglayer, with reference to the schematic cross sectional views. FIG. 10 isa schematic enlarged plan view of an organic light emitting panel in acomparative example pertaining to at least one embodiment. FIG. 10indicates, similarly to FIG. 2, the configuration near the boundarybetween an image display region and a peripheral region. FIGS. 11A and11B are schematic cross sections respectively taken along lines C-C andD-D in FIG. 10, indicating the configuration of the organic lightemitting panel in the comparative example pertaining to at least oneembodiment.

In the comparative example in FIG. 10, a liquid-repellent peripheralbank 320 is formed directly on a peripheral electrode 300 with nolyophilic insulating layer therebetween. In the comparative example, anuncured material resist layer is removed by using a developer in apatterning process of the peripheral bank 320 and column banks 522Y. Atthis time, a common electrode 126 and a sealing layer 127 have not beenyet formed. Accordingly, part of a surface part of a peripheralelectrode 300 that is not covered with the peripheral bank 320 isexposed to the developer. As described above, since the peripheral bank320 and the column banks 522Y include fluorine compound for the purposeof exhibiting liquid-repellency, the developer includes fluorinecompound. In contrast, the peripheral electrode 300 includes a metalmaterial. Due to this, the exposed surface part of the peripheralelectrode 300 reacts with the fluorine compound included in thedeveloper, and thus partially elutes. Especially when such a reactionoccurs at the interface between the peripheral bank 320 and theperipheral electrode 300, part of the peripheral electrode 300 that isin contact with the peripheral bank 320 elutes. Thus, a crack isgenerated at the interface between the peripheral bank 320 and theperipheral electrode 300. As a result, the outer edge of the peripheralbank 320 partially floats up from the peripheral electrode 300, and thisgreatly decreases the adhesion between the peripheral bank 320 and theperipheral electrode 300. Thus, in an application process of lightemitting layers, a so-called color mixture might occur due to inkleakage through gaps generated by the separated the peripheral bank 320.If a developing period in formation of the peripheral bank 320 isreduced, a period during which the surface part of the peripheralelectrode 300 is in contact with the developer is accordingly reduced.This resolves the concern about separation between the peripheral bank320 and the peripheral electrode 300, but raises another concern thatsufficient removal of an uncured material resist layer might beimpossible. In other words, the comparative example has an antinomy.When corrosion of the surface part of the peripheral electrode 300 isprevented, a defect in formation occurs such as a defect in shape of theperipheral bank 320 and the column banks 522Y and a defect that aliquid-repellent insulating layer is formed in a portion where such aninsulating layer is unnecessary.

Compared with this, in the display panel 10 pertaining to at least oneembodiment, the lyophilic insulating layer 310 is located between atleast the outer edge of the peripheral bank 320 and the peripheralelectrode 300. In the display panel 10 pertaining to at least oneembodiment as well as the comparative example, in a patterning processof the peripheral bank 320 and the column banks 522Y, an uncuredmaterial resist layer is removed by using a developer, and thus asurface part of the peripheral electrode 300 that is not covered withthe lyophilic insulating layer 310 is exposed to the developer. However,since the lyophilic insulating layer 310 has a lower percentage offluorine compound than the peripheral bank 320 or includes no fluorinecompound, corrosion of the surface of the peripheral electrode 300 atthe interface between the lyophilic insulating layer 310 and theperipheral electrode 300 is prevented. Furthermore, since the lyophilicinsulating layer 310 is disposed between the surface of the peripheralelectrode 300 and the peripheral bank 320, the developer has, at theinterface between the lyophilic insulating layer 310 and the peripheralelectrode 300, a low concentration of fluorine compound compared withthe case where the lyophilic insulating layer 310 is not provided. Thishelps to prevent separation of the peripheral bank 320. The inventorsmade a test for checking whether the peripheral bank 320 separates inextended developing periods in order to validate the effect ofpreventing separation of the peripheral bank 320. The following tableindicates results of the test. Here, the developing period in the tableindicates a developing period in formation of the column banks 522 thatis defined on the basis of a developing period of 1 that is a periodnecessary for completely removing resist in the entire surface of apredefined part of self light emitting regions 100 a where lightemitting layers and so on are to be formed. In the comparative example,little margin was left for the developing period. In the examplepertaining to at least one embodiment, in contrast, the peripheral bank320 did not separate even in a period 1.4 times the developing period.

TABLE 1 Separation Developing period (a.u.) 1.0 1.1 1.4 Example No No NoComparative example No Yes YesThus, a sufficient developing period is allocated in formation of theperipheral bank 320, the column banks 522Y, and so on. This helps tosuppress defects in formation of the peripheral bank 320 and the columnbanks 522Y due to an insufficient developing period.4. Manufacturing Method of Display Panel 10

Next, a manufacturing method of the display panel 10 is described withreference to the drawings. FIGS. 5A to 5E and FIGS. 6A to 6D areschematic cross sections taken along the line A-A in FIG. 2, indicatingstates of processes in manufacturing of the display panel 10 pertainingto at least one embodiment. FIGS. 7A to 7E and FIGS. 8A to 8D areschematic cross sections taken along the line B-B in FIG. 2, indicatingstates of processes in manufacturing of the display panel 10 pertainingto at least one embodiment. Also, FIGS. 9A to 9C are schematic planviews indicating states of processes in manufacturing of the displaypanel 10 pertaining to at least one embodiment. Moreover, FIG. 4 is aflow chart of the manufacturing method of the display panel 10pertaining to at least one embodiment.

(1) Formation of Substrate 100 x

Firstly, in FIGS. 5A and 7A, a substrate 100 x is formed by forming aTFT layer on a base material and forming an interlayer insulating layeron the TFT layer (Step S10). The TFT later is formed by a known TFTmanufacturing method. The interlayer insulating layer is formed forexample by a plasma CVD method or a sputtering method.

Next, contact holes are provided in the interlayer insulating layer byperforming dry-etching so as to be located on parts of source electrodesof the TFT layer. The contact holes are provided such that bottomsurfaces of the source electrodes are exposed in bottoms of the contactholes.

Next, connection electrode layers are formed along inner walls of thecontact holes. Upper parts of the connection electrode layers arepartially disposed on the interlayer insulating layer. The connectionelectrode layers are formed by forming a metal film for example by thesputtering method, and then patterning the metal film by aphotolithography method and a wet etching method.

(1) Formation of Pixel Electrodes 119 and Peripheral Electrode 300

Next, in FIGS. 5B and 7B, a pixel electrode material layer 119X isformed on the substrate 100 x (Step S20). The pixel electrode materiallayer 119X is formed for example by the vacuum deposition method or thesputtering method.

Then, in FIGS. 5C and 7C, pixel electrodes 119 and a peripheralelectrode 300 are formed by patterning the pixel electrode materiallayer 119X by an etching method (Step S30). While the pixel electrodes119 are located in an image display region 10 a so as to be partitionedbetween sub pixels 100 se, the peripheral electrode 300 is located in aperipheral region 10 b. A plan view of the pixel electrodes 119 and theperipheral electrode 300 after formation is as in the schematic view ofFIG. 9A.

(3) Formation of Row Banks 122X and Lyophilic Insulating Layer 310

Next, in FIGS. 5D and 7D, a first resist layer 122A is formed byapplying photosensitive resin, which is a material of row banks 122X anda lyophilic insulating layer 310, onto the pixel electrodes 119, theperipheral electrode 300, and the substrate 100 x (Step S40). Thephotosensitive resin is for example phenol resin, which is a positivephotosensitive material. Specifically, the first resist layer 122A isformed by uniformly applying a solution of phenol resin dissolved in asolvent onto the pixel electrodes 119, the peripheral electrode 300, andthe substrate 100 x for example by a spin coating method.

Then, in FIGS. 5E and 7E, the row banks 122X and the lyophilicinsulating layer 310 are formed by performing pattern exposure anddeveloping on the first resist layer 122A (Step S50). A plan view of therow banks 122X and the lyophilic insulating layer 310 after formation isas in the schematic view of FIG. 9B. The row banks 122X are formed so asto partially cover each pair of the pixel electrodes 119 adjacent in thecolumn direction and cover the contact holes. In contrast, the lyophilicinsulating layer 310 has a frame shape with a predefined width, and isdisposed on the peripheral electrode 300 such that the outer edge of thelyophilic insulating layer 310 is located outside the outer edge of aperipheral bank 320. In FIG. 9B, in at least one embodiment, the rowbanks 122X and the lyophilic insulating layer 310 are continuous withoutbeing separated near the boundary between the image display region 10 aand the peripheral region 10 b.

(4) Formation of Column Banks 522Y and Peripheral Bank 320

Next, in FIGS. 6A and 8A, a second resist layer 522A is formed byapplying photosensitive resin, which is a material of column banks 522Yand the peripheral bank 320, onto the pixel electrodes 119, theperipheral electrode 300, and the substrate 100 x (Step S60). Thephotosensitive resin is for example phenol resin, which is a positivephotosensitive material, to which fluorine compound, which is aliquid-repellent surfactant, has been added. Specifically, the secondresist layer 522A is formed by uniformly applying a solution of phenolresin dissolved in a solvent onto the pixel electrodes 119, theperipheral electrode 300, and the substrate 100 x for example by thespin coating method.

Then, in FIGS. 6B and 8B, the column banks 522Y and the peripheral bank320 are formed by performing pattern exposure and developing on thesecond resist layer 522A (Step S70). A plan view of the column banks522Y and the peripheral bank 320 after formation is as in the schematicview of FIG. 9C. The column banks 522Y are formed so as to partiallycover each pair of the pixel electrodes 119 adjacent in the rowdirection and cover the row banks 122X. In contrast, the peripheral bank320 has a frame shape with a predefined width, and is disposed on thelyophilic insulating layer 310 such that at least the outer edge of theperipheral bank 320 is located on the lyophilic insulating layer 310. InFIG. 9C, in at least one embodiment, the row banks 122X and thelyophilic insulating layer 310 are continuous without being separatednear the boundary between the image display region 10 a and theperipheral region 10 b.

Lastly, the row banks 122X, the lyophilic insulating layer 310, thecolumn banks 522Y, and the peripheral bank 320 are collectively bakedfor example at a temperature of 150 degrees C. to 210 degrees C. for 60minutes.

(5) Formation of Functional Layer

Next, hole injection layers 120 are formed by applying an ink containingmaterial of the hole injection layers 120 to openings which are definedby the row banks 122X and the column banks 522Y and baking (drying) theapplied ink. Next, hole transport layers 121 are formed by applying anink containing material of the hole transport layers 121 onto the holeinjection layers 120 in the openings and baking (drying) the applied ink(Step 80).

Next, light emitting layers 123 are formed by applying an ink containingmaterial of the light emitting layers 123 onto the hole transport layers121 in the openings and baking (drying) the applied ink (Step S90).

Next, an electron transport layer 124 is formed by forming a film frommaterial of the electron transport layer 124 on the light emittinglayers 123, the row banks 122X, and the column banks 522Y over the imagedisplay region 10 a in common for the sub pixels 100 se by the vacuumdeposition method or the sputtering method. Next, an electron injectionlayer 125 is formed by forming a film from material of the electroninjection layer 125 on the electron transport layer 124 in common forthe sub pixels 100 se by the vacuum deposition method, the spin coatingmethod, a cast method, or the like (Step S100). FIGS. 6C and 8C indicatethe state of the electron transport layer 124 immediately afterformation.

(6) Formation of Common Electrode 126

Next, a common electrode 126 is formed by forming a film from materialof the common electrode 126 on the electron injection layer 125, thelyophilic insulating layer 310, the peripheral bank 320, and theperipheral electrode 300 in common for the sub pixels 100 se and theperipheral electrode 300 by the vacuum deposition method or thesputtering method (Step S110).

(7) Formation of Sealing Layer 127

Lastly, in FIGS. 6D and 8D, a sealing layer 127 is formed by forming afilm using material of the sealing layer 127 on the common electrode 126in common for the sub pixels 100 se by a CVD method or the sputteringmethod (Step S120).

The display panel 10 is complete through the above processes.

In at least one embodiment, an upper substrate, and so on are adheredonto the sealing layer 127.

5. Whole Configuration of Organic EL Display Device

FIG. 12 is a schematic block diagram of configuration of an organic ELdisplay device 1000 that includes the display panel 10 pertaining to atleast one embodiment. In FIG. 12, the organic EL display device 1000includes the display panel 10 and a drive control unit 200 that isconnected to the display panel 10. The drive control unit 200 includesfour drive circuits 210 to 240 and a control circuit 250.

In actual organic EL display devices 1000, the arrangement of the drivecontrol unit 200 relative to the display panel 10 is not limited to theabove arrangement.

(1) In at least one embodiment, the lyophilic insulating layer 310 islocated both inside and outside the outer edge of the peripheral bank320 in plan view. Also, in at least one embodiment, the lyophilicinsulating layer 310 is interposed between the peripheral electrode 300and the peripheral bank 320 so as to be disposed immediately below theouter edge of the peripheral bank 320 and a part immediately inside theouter edge and on the peripheral electrode 300 in plan view. Forexample, the outer edge of the lyophilic insulating layer 310 coincideswith the outer edge of the peripheral bank 320 in plan view.

Also, in a peripheral bank developing process, a surface part of theperipheral electrode that is not covered by the peripheral bank isexposed to a developer, and thus elutes. As a result, the peripheralbank separates from the substrate. This phenomenon tends to occur morefrequently in a bent part of a bottom surface of the peripheral bank 320than in a linear part of the bottom surface of the peripheral bank 320,and tends to occur most frequently in a corner part of the bottomsurface of the peripheral bank 320. In view of this, in at least oneembodiment, the lyophilic insulating layer 310 is interposed between theperipheral electrode 300 and the peripheral bank 320 so as to bedisposed immediately below only the bent part of the outer edge of theperipheral bank 320, that is, immediately below at least the corner partof the bottom surface of the peripheral bank 320 and on the peripheralelectrode 320.

(2) In at least one embodiment, the peripheral bank 320 is formed so asto surround the image display region with no gap. Also, in at least oneembodiment, the peripheral bank 320 has for example a shape like twoparallel lines so as to close both ends in the column direction of theimage display region 10 a (the upper end and the lower end of the imagedisplay region 10 a in FIG. 1) corresponding to the both ends of thecolumn banks 522Y in the column direction. Furthermore, in at least oneembodiment, the peripheral bank 320 for example has a part that isparallel to the column banks 522Y and is partially cut and/or a partthat is in contact with the row banks 122X and is partially cut. In thiscase, the lyophilic insulating layer 310 is interposed between theperipheral electrode 300 and the peripheral bank 320 so as to bedisposed immediately below the outer edge of the peripheral bank 320 andon the peripheral electrode 300 in the peripheral region 10 b.

Moreover, in at least one embodiment, in the similar manner to theperipheral bank 320, in the case where any bank like the column banks522Y, such as a bank that is rectangular and partitions dummy pixelregions, is provided in the peripheral region 10 b, the lyophilicinsulating layer 310 is interposed between the peripheral electrode andthe bank so as to be disposed immediately below the outer edge of thebank and on the peripheral electrode 300.

(3) In at least one embodiment, the peripheral electrode 300 is formedso as to surround the image display region 10 a with no gap. Also, in atleast one embodiment, the peripheral electrode 300 is for example formedalong the column banks 522Y only outside the image display region 10 ain the row direction (on the left and right sides outside the imagedisplay region 10 a in FIG. 1). Moreover, in at least one embodiment,the peripheral electrode 300 is formed in separate regions. Also, in atleast one embodiment, other electrode is for example be disposed in theperipheral region 10 b in addition to the peripheral electrode 300. Inthe case where a peripheral bank is disposed on the other electrode, thelyophilic insulating layer 310 is interposed between the other electrodeand the peripheral bank so as to be disposed immediately below the outeredge of the peripheral bank and on the other electrode.

(4) In at least one embodiment, the pixel electrodes 119 and theperipheral electrode 300 are formed simultaneously by using the samematerial, the row banks 122X and the lyophilic insulating layer 310 areformed simultaneously by using the same material, and the column banks522Y and the peripheral bank 320 are formed simultaneously by using thesame material. Also, in at least one embodiment, the pixel electrodes119 and the peripheral electrode 300 are for example formed separately,and/or the column banks 522Y and the peripheral bank 320 are for exampleformed separately.

(4) In at least one embodiment, the organic EL display panel includesthe light emitting layers of three types emitting light of the threecolors R, G, and B. Also, in at least one embodiment, the light emittinglayers are of two types or four or more types. Here, the types of lightemitting layers indicate variation in film thickness of light emittinglayers, a functional layer, and the like. Light emitting layers, afunctional layer, and the like that emit light of the same color buthave different film thicknesses can be regarded as light emitting layersof different types. Also, the arrangement order of the light emittinglayers is not limited to RGBRGB. . . . In at least one embodiment, lightemitting layers are arranged in the order of RGBBGRRGB. . . .Furthermore, in at least one embodiment, auxiliary electrode layers,other non-luminous regions, etc. are provided between pixels. In atleast one embodiment, auxiliary electrode layers are provided so as tobe electrically connected with the peripheral electrode 300. Moreover,in at least one embodiment, the auxiliary electrode layers are formedsimultaneously with at least one of the pixel electrodes 119 and theperipheral electrode 300 by using the same material as at least one of amaterial of the pixel electrodes 119 and a material of the peripheralelectrode 300.

(5) In at least one embodiment, the hole injection layers 120, the holetransport layers 121, and the light emitting layers 123 in the organicEL elements 100 are all formed by an application method. Also, in atleast one embodiment, these layers are formed by other method such asthe deposition method and the sputtering method.

Moreover, the organic EL elements 100 do not necessarily need to havethe above configuration including the hole injection layers 120, thehole transport layers 121, the electron transport layer 124, and theelectron injection layer 125. In at least one embodiment, organic ELelements 100 do not include at least one of these layers. Also, in atleast one embodiment, organic EL elements 100 include other functionallayer in addition to these layers. Furthermore, in at least oneembodiment, the organic EL elements 100 include a single electroninjection transport layer instead of the electron transport layer 124and the electron injection layer 125.

(6) In at least one embodiment, since the display panel 10 is of thetop-emission type, the pixel electrodes are light-reflective and thecommon electrode is light-transmissive. Also, in at least oneembodiment, a display panel is of a so-called bottom-emission type.

(7) In at least one embodiment, the display panel 10 includes theorganic EL elements 100 of an application type as light emittingelements. Also, in at least one embodiment, the display panel 10 includeorganic EL elements of a deposition type as light emitting elements.Moreover, the present disclosure is not limited to organic lightemitting panels, and may include inorganic light emitting panels havinglight emitting elements other than organic EL light emitting elements,and non-self light emitting panels such as liquid crystal panels. Thepresent disclosure is effective in the case where display panels includeelements that are formed by forming a resist pattern containing fluorinein a wide range on a metal layer that is damaged in developing ofphotolithography.

Although the technology pertaining to the present disclosure has beenfully described by way of examples with reference to the accompanyingdrawings, it is to be noted that various changes and modifications willbe apparent to those skilled in the art. Therefore unless such changesand modifications depart from the scope of the present disclosure, theyshould be construed as being included therein.

The invention claimed is:
 1. A display panel comprising: a substrate; alight emitting element array that is disposed above the substrate in animage display region; a peripheral electrode that is disposed above thesubstrate in a peripheral region, the peripheral region being locatedoutside the image display region in plan view; a lyophilic insulatinglayer that is disposed on the peripheral electrode; and a peripheralbank that includes a liquid-repellent resin material including fluorine,and has an outer edge that overlaps the peripheral electrode in theperipheral region in plan view, wherein the lyophilic insulating layerincludes a resin material having a lower percentage of fluorine than theperipheral bank, and at least a corner part of a bottom surface of theperipheral bank is disposed on the lyophilic insulating layer.
 2. Thedisplay panel of claim 1, wherein the resin material of the lyophilicinsulating layer includes no fluorine.
 3. The display panel of claim 1,wherein the peripheral bank partitions between the image display regionand the peripheral region.
 4. The display panel of claim 1, wherein anouter edge of the lyophilic insulating layer is located outside theouter edge of the peripheral bank in plan view.
 5. The display panel ofclaim 1, wherein an outer edge of the lyophilic insulating layercoincides with the outer edge of the peripheral bank in plan view. 6.The display panel of claim 1, wherein the light emitting element arrayincludes light emitting elements that include pixel electrodes, afunctional layer, and a common electrode, and the peripheral electrodeand the pixel electrodes include a same material.
 7. The display panelof claim 6, wherein the peripheral electrode is electrically connectedwith the common electrode.
 8. The display panel of claim 1, wherein thelight emitting element array includes: light emitting elements that aredisposed in a matrix of rows and columns; column banks that include aliquid-repellent resin material, extend in a column direction, andpartition between the light emitting elements in a row direction; androw banks that include a resin material having a lower liquid repellencythan the column banks, and partition between the light emitting elementsin the column direction, and the lyophilic insulating layer and the rowbanks include a same material.
 9. The display panel of claim 8, whereinthe peripheral bank and the column banks include a same material.
 10. Adisplay device comprising the display panel of claim
 1. 11. A displaypanel comprising: a substrate; a light emitting element array that isdisposed above the substrate in an image display region; a peripheralelectrode that is disposed above the substrate in a peripheral region,the peripheral region being located outside the image display region inplan view; a lyophilic insulating layer that is disposed on theperipheral electrode; and a peripheral bank that includes aliquid-repellent resin material including fluorine, wherein thelyophilic insulating layer includes a resin material having a lowerpercentage of fluorine than the peripheral bank, a part of an outer edgeof the peripheral bank overlaps the peripheral electrode in theperipheral region in plan view, and at least the part of the outer edgeof the peripheral bank is disposed on the lyophilic insulating layer.12. A method of manufacturing a display panel having an image displayregion and a peripheral region, the peripheral region being locatedoutside the image display region in plan view, the method comprising:forming pixel electrodes above a substrate in a range corresponding tothe image display region; forming a peripheral electrode above thesubstrate in a range corresponding to the peripheral region; forming alyophilic insulating layer and row banks by using a photosensitive resinmaterial, wherein the lyophilic insulating layer covers at least aninner edge of the peripheral electrode, and the row banks partitionbetween the pixel electrodes in a column direction; forming a peripheralbank and column banks by using a photosensitive resin material having ahigher percentage of fluorine than the photosensitive resin material ofthe lyophilic insulating layer, wherein at least a corner part of abottom surface of the peripheral bank is disposed on the lyophilicinsulating layer, and the column banks partition between the pixelelectrodes in a row direction; forming a functional layer above thepixel electrodes; and forming a common electrode above the functionallayer and the peripheral electrode.
 13. A method of manufacturing adisplay panel having an image display region and a peripheral region,the peripheral region being located outside the image display region inplan view, the method comprising: forming pixel electrodes above asubstrate in a range corresponding to the image display region; forminga peripheral electrode above the substrate in a range corresponding tothe peripheral region; forming a lyophilic insulating layer and rowbanks by using a photosensitive resin material, wherein the lyophilicinsulating layer covers at least an inner edge of the peripheralelectrode, and the row banks partition between the pixel electrodes in acolumn direction; forming a peripheral bank and column banks by using aphotosensitive resin material having a higher percentage of fluorinethan the photosensitive resin material of the lyophilic insulatinglayer, wherein an outer edge of the peripheral bank is located inside anouter edge of the lyophilic insulating layer, and the column bankspartition between the pixel electrodes in a row direction; forming afunctional layer above the pixel electrodes; and forming a commonelectrode above the functional layer and the peripheral electrode.